Abstract: Immature and mature zygotic embryos of Larix gmelinii were as explants to induce embryogenic callus. Several factors influencing the induction were assayed. The induction rate(IR) of embryogenic callus(EC) from zygotic embryo(ZE) explant with its endosperms was higher than that from ZE explant without its endosperms. The IR of EC from mature ZE explant from Inner Mongolia seed source was significantly higher than that which from Daxing’an Mountains seed source（p<0.05）. The IR of EC from mature ZE explant derived from seeds stored at 4℃ for two months could be improved evidently. The IR of EC from immature ZE explants derived from seeds collected in different developmental stages was significant different, highest IR of EC could be obtained from immature ZE explant collected on July 5. 2,4-D had greater effects on EC induction than BA and KT, and these three hormones had certain co-efficient effects. S medium was more effective than MS and DCR media. Higher IR could be obtained on medium with 4 g·L^-1 agar.

Key words: Larix gmelinii, somatic embryogenesis, embryogenic callus, zygotic embryo explants